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International Journal of Science and Engineering (IJSE)
Published by Universitas Diponegoro
ISSN : -     EISSN : -     DOI : -
Core Subject : Engineering,
The scope of journal covers all area in the application on chemical, physical, mathematical, biological, agricultural, corrossion, and computer science to solve the engineering problems.
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Articles 15 Documents
Search results for , issue " Vol 8, No 1 (2015)" : 15 Documents clear
Snap-Through Buckling Problem of Spherical Shell Structure Sumirin, Sumirin; Nuroji, Nuroji; Besari, Sahari
International Journal of Science and Engineering Vol 8, No 1 (2015)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1336.92 KB) | DOI: 10.12777/ijse.8.1.54-59

Abstract

This paper presents results of a numerical study on the nonlinear behavior of shells undergoing snap-through instability. This research investigates the problem of snap-through buckling of spherical shells applying nonlinear finite element analysis utilizing ANSYS Program. The shell structure was modeled by axisymmetric thin shell of finite elements. Shells undergoing snap-through buckling meet with significant geometric change of their physical configuration, i.e. enduring large deflections during their deformation process. Therefore snap-through buckling of shells basically is a nonlinear problem. Nonlinear numerical operations need to be applied in their analysis. The problem was solved by a scheme of incremental iterative procedures applying Newton-Raphson method in combination with the known line search as well as the arc- length methods. The effects of thickness and depth variation of the shell is taken care of by considering their geometrical parameter l. The results of this study reveal that spherical shell structures subjected to pressure loading experience snap-through instability for values of l≥2.15. A form of ‘turn-back’ of the load-displacement curve took place at load levels prior to the achievement of the critical point. This phenomenon was observed for values of l=5.0 to l=7.0.
PROCESSING OF WATERMELON RIND DEHYDRATED CANDY Muhamad, Nur Farah Hani; Wan Zainon, Wan Nur Zahidah; Kormin, Saniah; Mohd. Akhir, Nurasmaliza; Ali, Muhammad Shah
International Journal of Science and Engineering Vol 8, No 1 (2015)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (23.552 KB) | DOI: 10.12777/ijse.8.1.6-9

Abstract

Watermelon rind (Citrullus lanatus) dehydrated candy was prepared by using osmotic dehydration process that involves slow impregnation of syrup before drying at 50°C for 8, 14 and 20 hours. From the study, it can be seen that drying time significantly affected the moisture content of the watermelon rind dehydrated candy. The moisture content was significantly decreased with drying time. For colour evaluation, the L* value of watermelon rind dehydrated candy was slightly decreased with drying time while the a* value was slightly increased. Watermelon rind dehydrated candy that dried for 14 hours was the most preferred sample by the panelists as it received the highest score for texture, taste and overall acceptability attributes.  So, it can be concluded that 14 hours of drying time is the most appropriate time to dry the candied watermelon rind.  
Synthesis of poly(Oxide propylene -co- para nitro Benzaldehyde)–clay nanocomposites Mrah, lahouari; rachid, meghabar; Mohammed, Belbachir
International Journal of Science and Engineering Vol 8, No 1 (2015)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (40.123 KB) | DOI: 10.12777/ijse.8.1.

Abstract

Abstract; A reactive cationic surfactant cetyltrimethylamonium bromide (CTAB)  was synthesized for intercalation of  montmorillonite (MMT), the  poly(Oxide propylene -co- para nitro Benzaldehyde) PPOCPB /clay nanocomposites  were prepared  by using  cetyltrimethylammonium bromide (CTAB)  intercalated  montmorillonite  as the supporting matrix. CTAB-Maghnite is a montmorillonite silicate sheet clay was prepared through a Straight forward exchange process, using a green natural clay from Maghnia (west of Algeria).The formation of copolymers was confirmed by X-ray diffraction (XRD), differential scanning calorimetry (DSC), the Mt interlayer spaces was studied by means of Fourier transform infrared (FTIR)and force atomic microscopy (AFM) indicate that exfoliation of MMT was achieved.
PRELIMINARY STUDY OF SEAWEED DRYING UNDER A SHADE AND IN A NATURAL DRAFT SOLAR DRYER Phang, Hooi-Kim; Chu, Chi-Ming; Kumaresan, Sivakumar; Rahman, Md. Mizanur; Yasir, Suhaimi Md.
International Journal of Science and Engineering Vol 8, No 1 (2015)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (270.505 KB) | DOI: 10.12777/ijse.8.1.10-14

Abstract

A solar dryer was designed to study the seaweed drying process under natural convection and compared to a shade drying process. A dewatering pre-treatment process was initially applied to enhance drying process for both methods. The initial weight of seaweed before pre-treatment and after pre-treatment was recorded and the seaweed was then introduced into the solar drying system and shade drying system. The air temperature and relative humidity inside the solar dryer and surrounding were recorded during experiment. A representative sample on each tray was taken for final moisture content determination where the difference of seaweed weight less than 5% for subsequent measurement. The average weight loss of seaweed from pre-treatment was about 54%. The final moisture content of seaweed for solar drying was in the range of 24-61% (d.b.) and for shade drying was in the range of 40-48% (d.b.) with a standard deviation of final moisture content of 20.45% for solar drying and 3.78% for shade drying. The total time for solar drying inclusive of pre-treatment was 6 days and shade drying was 9 days. The drying kinetics of each method was modeled and the results of this study will be utilized to enhance the design and operations of seaweed solar dryers.
Reliability based design optimization of concrete mix proportions using generalized ridge regression model Aggarwal, Rachna; Kumar, Maneek; Sharma, R.K.; Sharma, M.K.
International Journal of Science and Engineering Vol 8, No 1 (2015)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (303.24 KB) | DOI: 10.12777/ijse.8.1.26-37

Abstract

This paper presents Reliability Based Design Optimization (RBDO) model to deal with uncertainties involved in concrete mix design process. The optimization problem is formulated in such a way that probabilistic concrete mix input parameters showing random characteristics are determined by minimizing the cost of concrete subjected to concrete compressive strength constraint for a given target reliability.  Linear and quadratic models based on Ordinary Least Square Regression (OLSR), Traditional Ridge Regression (TRR) and Generalized Ridge Regression (GRR) techniques have been explored to select the best model to explicitly represent compressive strength of concrete. The RBDO model is solved by Sequential Optimization and Reliability Assessment (SORA) method using fully quadratic GRR model. Optimization results for a wide range of target compressive strength and reliability levels of 0.90, 0.95 and 0.99 have been reported. Also, safety factor based Deterministic Design Optimization (DDO) designs for each case are obtained. It has been observed that deterministic optimal designs are cost effective but proposed RBDO model gives improved design performance.
APPLICATION OF WELL LOG ANALYSIS IN ASSESSMENT OF PETROPHYSICAL PARAMETERS AND RESERVOIR CHARACTERIZATION OF WELLS IN THE “OTH” FIELD, ANAMBRA BASIN, SOUTHERN NIGERIA URORO, Eugene; IGHARO, Efe Lucky
International Journal of Science and Engineering Vol 8, No 1 (2015)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1284.501 KB) | DOI: 10.12777/ijse.8.1.47-53

Abstract

Over the past years, the Anambra basin one of Nigeria’s inland basins has recorded significant level of hydrocarbon exploration activities. The basin has been confirmed by several authors from source rock analyses to have the potential for generating hydrocarbon. For the hydrocarbon to be exploited, it is imperative to have a thorough understanding of the reservoir. Computer-assisted log analyses were employed to effectively evaluate the petrophysical parameters such as the shale volume (Vsh), total porosity (TP), effective porosity (EP), water saturation (Sw), and hydrocarbon saturation (Sh). Cross-plots of the petrophysical parameters versus depth were illustrated. Five hydrocarbon bearing reservoirs were delineated in well 1, four in well 2. The reservoirs in well 3 do not contain hydrocarbon. The estimated reservoir porosity varies from 10% to 21% while their permeability values range from 20md to 1400md. The porosity and permeability values suggest that reservoirs are good enough to store and also permit free flow of fluid. The volume of shale (0.05% to 0.35%) analysis reveals that the reservoirs range from shaly sand to slightly shaly sand to clean sand reservoir. On the basis of petrophysics data, the reservoirs are interpreted a good quality reservoir rocks which has been confirmed with high effective porosity range between 20% and high hydrocarbon saturation exceeding 55% water saturation in well 1 and well 2. Water saturation 3 is nearly 100% although the reservoir properties are good.  
A HIGH ORDER SOLUTION OF THREE DIMENSIONAL TIME DEPENDENT NONLINEAR CONVECTIVE-DIFFUSIVE PROBLEM USING MODIFIED VARIATIONAL ITERATION METHOD Joshi, Pratibha; Pathak, Maheshwar
International Journal of Science and Engineering Vol 8, No 1 (2015)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1061.019 KB) | DOI: 10.12777/ijse.8.1.1-5

Abstract

In this paper, we have achieved high order solution of a three dimensional nonlinear diffusive-convective problem using modified variational iteration method. The efficiency of this approach has been shown by solving two examples. All computational work has been performed in MATHEMATICA.
Drying Characteristics and Product Quality of Lemon Slices Dried with Hot Air Circulation Oven and Hybrid Heatpump Dryers Lee, Yong Hong; Chin, Siew Kian; Chung, Boon Kuan
International Journal of Science and Engineering Vol 8, No 1 (2015)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (415.232 KB) | DOI: 10.12777/ijse.8.1.69-74

Abstract

In this research, drying characteristics and product quality of Coulomb-force-assisted heatpump and oven dried lemon slices were studied. Lemon slices with 3 mm thickness each, were dried using oven and Coulomb-force-assisted-heatpump dryer with and without auxiliary heater at different drying conditions. It was found that the drying rate of the lemon slices dried by all drying methods showed only falling rate states, which indicates the drying kinetics were controlled by internal moisture diffusion. Oven drying of lemon slices at 60°C showed the highest drying rate among all, followed by oven dried slices at 50°C, Coulomb-force-heater-assisted-heatpump (CF-HT-HP) dried slices at 31°C, Coulomb-force-assisted-heatpump (CF-HP) dried slices at 22°C, oven dried slices at 40°C and heatpump dried slices at 22°C. The average effective moisture diffusivity value for the slices dried with these drying methods was found in the range of 16.2 to 63.8´10-4 mm2min-1. In terms of quality assessment, CF-HP dried lemon slices retained the highest amount of Vitamin C as compared to the lemon slices dried by other drying methods. However, it retained relatively lower amount of total phenolic content (TPC) as compared to oven dried products. Among of all, CF-HP drying method produced dried lemon slices with the highest Vitamin C (6.74 mg AA / g dry weight) whereas oven dried lemon slices at 50°C preserved most of the TPC in the dried slices, which recorded as 13.76 mg GA / g dry weight.
Profile Triglycerides Japanese Quail (Coturnix coturnix japonica) After Giving Turmeric (Curcuma longa) Powder Putra, Sukarman Hadi jaya; Saraswati, Tyas Rini; Isdadiyanto, Sri
International Journal of Science and Engineering Vol 8, No 1 (2015)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (130.56 KB) | DOI: 10.12777/ijse.8.1.65-68

Abstract

The purpose of this study was to determine the triglyceride profile of Japanese quail (Coturnix coturnix japonica) after being given the parameters of turmeric (Curcuma longa) powder; feed intake, profiles of liver triglycerides, profiles of serum triglycerides and profiles of meat triglycerides. This study uses an experimental method with A Completely Randomized Design Pattern. Test animals used were 45 female Japanese quails were divided into 3 groups, namely; P0: quail were not given turmeric powder, P1: quail were given turmeric powder a dose of 54 mg/quail/day, P3: quail were given turmeric powder a dose of 108 mg/quail/day. Each group with 5 replications. Each repeat consists of 3 Japanese quails. Provision of treatment every day for 30 days starting from the age of 14 days. Data were analyzed using analysis of variance (ANOVA) followed by Duncans test with 95% confidence interval (α = 0.05 level). Analysis of the data used is software Minitab software 16. Results showed that the levels of turmeric powder are given in Japanese quail significant (P˂0.05) on liver triglyceride levels, serum and Japanese quail meat but had no significant effect (P˃0.05) on consumption feed. The results showed that the optimal dose of turmeric powder to lower triglyceride levels of Japanese quail is 108 mg/quail/day as evidenced by the highest decrease in liver triglyceride profiles, profiles of serum triglycerides and triglyceride profiles of Japanese quail meat compared with other treatments.
Modelling of HTR (High Temperature Reactor) Pebble-Bed 10 MW to Determine Criticality as A Variations of Enrichment and Radius of the Fuel (Kernel) With the Monte Carlo Code MCNP4C Oktajianto, Hammam; Setiawati, Evi; Richardina, Very
International Journal of Science and Engineering Vol 8, No 1 (2015)
Publisher : Chemical Engineering Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (34.27 KB) | DOI: 10.12777/ijse.8.1.42-46

Abstract

Gas-cooled nuclear reactor is a Generation IV reactor which has been receiving significant attention due to many desired characteristics such as inherent safety, modularity, relatively low cost, short construction period, and easy financing. High temperature reactor (HTR) pebble-bed as one of type of gas-cooled reactor concept is getting attention. In HTR pebble-bed design, radius and enrichment of the fuel kernel are the key parameter that can be chosen freely to determine the desired value of criticality. This paper models HTR pebble-bed 10 MW and determines an effective of enrichment and radius of the fuel (Kernel) to get criticality value of reactor. The TRISO particle coated fuel particle which was modelled explicitly and distributed in the fuelled region of the fuel pebbles using a Simple-Cubic (SC) lattice. The pebble-bed balls and moderator balls distributed in the core zone using a Body-Centred Cubic lattice with assumption of a fresh fuel by the fuel enrichment was 7-17% at 1% range and the size of the fuel radius was 175-300 µm at 25 µm ranges. The geometrical model of the full reactor is obtained by using lattice and universe facilities provided by MCNP4C. The details of model are discussed with necessary simplifications. Criticality calculations were conducted by Monte Carlo transport code MCNP4C and continuous energy nuclear data library ENDF/B-VI. From calculation results can be concluded that an effective of enrichment and radius of fuel (Kernel) to achieve a critical condition was the enrichment of 15-17% at a radius of 200 µm, the enrichment of 13-17% at a radius of 225 µm, the enrichments of 12-15% at radius of 250 µm, the enrichments of 11-14% at a radius of 275 µm and the enrichment of 10-13% at a radius of 300 µm, so that the effective of enrichments and radii of fuel (Kernel) can be considered in the HTR 10 MW. Keywords—MCNP4C, HTR, enrichment, radius, criticality 

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